Methyl methacrylate is widely used as a monomer or comonomer in the preparation of shaped objects of polymethyl methacrylate such as sheet stock. Such polymethyl methacrylate sheeting is often used for glazing applications, and the clarity and color of the material is therefore important. Yellowness of the cast sheet is a common problem, and many solutions have been suggested to minimize or eliminate yellow color in the final product. At the same time, the elimination of the color must be done without depreciation of the physical properties of the sheeting or its clarity.